BOMBARDIER 1980 Shop Manual page 152

SECTION 03
SUB-SECTION 03, (IGNITION TIMING)
IGNITION TIMING - TWO CYLINDER ENGINES
(377, 444, 464, 503, 640 TYPES)
Two methods are detailed in this section; the first using
the timing marks stamped on the engine, the second
using a Top Dead Center gauge.
TIMING MARKS PROCEDURE
1. Disconnect spark plug wires and remove spark plugs.
2. Remove rewind starter assembly from engine then
remove the fan protector, starting pulley and "V" belt.
O
NaTE: The upper breaker point controls the timing
of the magneto side piston and the lower breaker
point controls the P,T,O. side piston.
3. Rotate crankshaft until breaker points, visible through
magneto ring opening, are fully opened. Adjust points
setting to 0.35 mm
±
0.05 (.014"
±
.002) using
a feeler gauge and screwdriver, as illustrated. Repeat
procedure for other point. Adjust both sides equally.
O
NaTE: Breaker points gap can change upon tight-
ening. Always recheck after tightening.
4. Disconnect junction block at engine then connect one
lead of a timing light (flashlight type) or of a tone timer,
to the blue wire (mag. side) leading from engine.
Connect other wire to ground (metallic portion of the
engine).
5. Slacken the two (2) armature plate retaining screws
and turn timing instrument ON. Rotate crakshaft until
mag. side piston approaches top dead center and
timing marks align (for 640 engine type, hold centrif-
ugal advance mechanism in full advance position).
(IGNITION TIMING), PAGE 4
d:::':;\
'>. '"
Retar?ed
" 'X:
pOSition
Full
advance
position
Rotate armature plate until timing light fluctuates or tone
signal level varies. Retighten retaining screws.
6. Ignition timing can change upon tightening therefore,
rotate the magneto counter-clockwise
t
of a turn and
slowly turn the magneto back in a clockwise direction.
As soon as the timing marks align the timing light
should fluctuate, or the tone signal level should vary.
Readjust if necessary.
~/ ~
~ ~
o
o
Too early: Turn armature plate clockWise